24小时热门版块排行榜

返回列表

当前主题已经存档。

当前只显示满足指定条件的回帖，点击这里查看本话题的所有回帖

Geochimica

木虫 (正式写手)

应助: 1 (幼儿园)
贵宾: 0.02
金币: 1745
散金: 42
红花: 1
帖子: 361
在线: 20.2小时
虫号: 440723
注册: 2007-10-27
性别: GG
专业: 生物地球化学

[交流] 【原创】简评Li et al., GEOLOGY, August 2009

Loess depositions in central China: Where do they come from?

The Chinese Loess Plateau located in central China has been covered by thick
loess sedimentations (> 100 m). The loess is thought to be the consequences of
Asian dust settlement which had been transported by wind from the vast arid
regions in far north or west. However, the exact location of where the loess
material comes from is poorly constrained. Distinguishing different sources
for Asian dust and deciphering the origin of ancient dust deposition – the
Chinese loess – would help us better understand the history of Asian dust
production and transportation, which would have profound paleoecology and
paleoclimate implications.
Gaojun Li and colleagues at Nanjing University employed paired radiogenic
isotope analyses, Neodymium (Nd) and Strontium (Sr), to survey all major
deserts or arid lands in China which could serve as potential dust sources.
They classified those deserts into three different areas with disparate
isotopic signatures. Since Nd-Sr isotopes are resistant to alterations during
dust production and transportation processes, Li et al. argue that the Nd-Sr
isotope analyses of both ancient (loess) and modern dust deposition could help
answering the question: where do they come from? Application of this
technique to Chinese loess reveals that instead of the closest deserts on the
Ordos Plateau, their origin relies in the northern margin of the Tibetan
Plateau thousands of kilometers away.

Journal Reference:
Natural and anthropogenic sources of East Asian dust
Gaojun Li, Jun Chen, Junfeng Ji, Jiedong Yang, and Tim M. Conway
http://bbs.nju.edu.cn/file/Earth ... st_Geology_2009.pdf

回复此楼